Biggest thing is to keep the batts. warm. I made a foam envelope from that 1/8 in foam that new electronics are wrapped in. Scotch taped together with a velcro closure. Was flying the other day at 18F with no problems. When I plug the batt in without the DX7 turned on the gyro will enitialize and come on solid red. then turn on the trans. and she's good to go. Put a few batts through it that day, didn't even break anything for a change.